影响鸢乌贼手钓上钩率的因子探讨

根据印度洋西北部鸢乌贼（Sym plectoteuthis oualaniensis）作业渔场的现场调查数据．分析了作业水深、作业时段、摄食等级和月相等因子对手钓上钩率的影响。统计表明．晚上、午夜和凌晨3个不同时段和不同作业水深对手钓上钩率均有显著性影响。3个时段中，其摄食等级呈先低后高再低的现象。午夜和凌展，上钩率的变化趋势与摄食等级的变化趋势呈显著的负相关。在月相的影响下．离朔日三四天之前，手钓产量呈上升趋势；离望日五六天之前。手钓产量呈明显的下降趋势。     

冰碛扇型砂金矿床特征及其成矿初探

成生于冰碛扇内，经一定的生物、物理、化学成矿作用，以砂金形态分布而富集成矿的金矿称为冰碛扇型砂金矿床。它具有沿造山带一定标高范围成群、成带分布，沉积物为近源且半胶结，砂金呈面状分布，并以粒金、块金为主，具胶状、浑圆状、包块状构造形态，分布极不均匀等特征。冰碛扇型砂金矿床的成矿作用与河成砂金矿床有本质的区别。它的成矿作用模式是：造山带下地壳富含的活化金通过新构造运动活化的断裂运移地表，经地下流体和地表流体的迁移聚集到冰碛扇这一封闭稳定的生物、物理、化学障环境中，主要经高效聚金微生物有机胶体成矿作用沉淀、再生加大形成砂金，逐步富集成矿床。而红色磨拉石建造中风化离解的Ｆｅ，Ｍｎ物质对沉淀环境ｐＨ值起着一定的调节作用。冰碛扇型砂金矿床在我国西部造山带内广泛分布，具有一定的工业价值，是砂金矿床中一重要类型，应予以重视     

A Simulating Experiment in the Process of Soil Erosion on Bare Land in Mt. Tanakami

In order to understand the process of surface erosion and acquire basic data of conditions on hillslope without vege tation, a sprinkling experiment is conducted on a bare slope in Mt. Tanakami in the central part of Japan. Based on the mea surements of runoff, mean soil erosion depth, and sediment yield, etc. , the results suggest the following characteristics in the process of surface erosion in the experimental area. (1) The occurrence of sediment discharge is interrupted; (2) Surface runoff is a saturated overland flow; (3) The mean soil erosion depth is thick compared with other areas in Mt. Tanakami;(4) Sediment discharge process is detachment- limited.     

Effect of Ploughing Depth on the Growth and Yield of Heracleum candicans： a Threatened Medicinal Herb and a Less-explored Potential Crop of the Himalayan Region

This paper examines the effect of ploughing depths （A -- 60 cm, B -- 45 cm and C -- 30 cm） on the growth and yield of Heracleum candicans Wall （Apiaceae）, a threatened medicinal herb of the Himalayan region. This less-explored plant is being suggested as a potential crop for the mountain agriculture. The study was carried out in an orchard in Himachal Pradesh, India at 2500 m altitude, for two successive growth years. During the first year, all plants remained in juvenile state; in the second year, nearly 65 % plants produced flowers only under 60cm ploughing depth. Among its morphological traits, plant height, collar diameter and aboveground flesh weight were found to be strongly correlated （P 〈 0.01） with the belowground biomass during the first year （r =0.968, 0.925 and 0.973, respectively） and during the second year （r=0.945, 0.928 and 0.775, respectively）. Increase in the ploughing depth was significantly correlated （P〈0.01） with all growth parameters, including the belowground dry weight, marketable portion of the produce. The belowground biomass （commercial yield; 16.28 Qt/hec） at depth A was about 2.6 and 4.7 times higher than those recorded at depths B and C, respectively. The results clearly justify the importance of deep ploughing and this paper strongly recommends it for economically sustainable cropping.     

广西芒场锡多金属矿田稳定同位素组成对矿床成因探讨

笔者曾对广西芒场锡多金属矿田的稳定同位素进行研究。本文根据硫、铅、氢、氧、碳等稳定同位素组成和锶的初始值提供的信息.探讨了矿床成因。并结合矿田矿床地质特征、控矿条件及有关统计参数,参考前人对矿床认识的基础上,修正提出了该矿田混合热液成矿模式,可供类似矿床研究和找矿的参考。     

松辽盆地中生代沉积基准面变化研究

利用地质资料研究来恢复沉积基准面变化。首先根据沉积物的分布规律、沉积构造、古生物组合及古生态、自生矿物和波基面等特征来获得古水深,然后利用对地层做脱水压实校正获得沉积物原始厚度。对湖盆地区古水深和沉积物原始厚度累加起来就可得到沉积基准面变化曲线。沉积基准面变化曲线为在松辽盆地中进行地层对比提供了依据。     

利用高光谱数据进行植被生化成分反演方法研究

高光谱数据包含着丰富光谱信息,能够定量地分析物质成分^[1]。由高光谱数据,可以运用多元逐步线性回归方法反演植被生化组分含量,从而达到监测植被生长状况的目的^[2]。本文具体介绍了多元逐步线性回归方法,及其在氮、木质素和纤维素含量估算中的应用。     

Detailed <Superscript>40</Superscript>Ar/<Superscript>39</Superscript>Ar dating of geologic events associated with the Mantos Blancos copper deposit,northern Chile

The ⁴⁰Ar/³⁹Ar geochronological method was applied to date magmatic and hydrothermal alteration events in the Mantos Blancos mining district in the Coastal Cordillera of northern Chile, allowing the distinction of two separate mineralization events. The Late Jurassic Mantos Blancos orebody, hosted in Jurassic volcanic rocks, is a magmatic-hydrothermal breccia-style Cu deposit. Two superimposed mineralization events have been recently proposed. The first event is accompanied by a phyllic hydrothermal alteration affecting a rhyolitic dome. The second mineralization event is related to the intrusion of bimodal stocks and sills inside the deposit. Because of the superposition of several magmatic and hydrothermal events, the obtained ⁴⁰Ar/³⁹Ar age data are complex; however, with a careful interpretation of the age spectra, it is possible to detect complex histories of successive emplacement, alteration, mineralization, and thermal resetting. The extrusion of Jurassic basic to intermediate volcanic rocks of the La Negra Formation is dated at 156.3 ± 1.4 Ma (2σ) using plagioclase from an andesitic lava flow. The first mineralization event and associated phyllic alteration affecting the rhyolitic dome occurred around 155–156 Ma. A younger bimodal intrusive event, supposed to be equivalent to the bimodal stock and sill system inside the deposit, is probably responsible for the second mineralization event dated at ca. 142 Ma. Other low-temperature alteration events have been dated on sericitized plagioclase at ca. 145–146, 125, and 101 Ma. This is the first time that two distinct mineralization events have been documented from radiometric data for a copper deposit in the metallogenic belt of the Coastal Cordillera of northern Chile. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

西藏驱龙超大型斑岩铜矿床:地质、蚀变与成矿

驱龙超大型矿床是一个产于后碰撞伸展环境下、与大洋俯冲无关的新型斑岩铜矿。文章通过对驱龙铜矿床地质、蚀变与矿化的详细研究,建立了驱龙中新世岩浆演化序列,初步查明了岩浆浅成侵位的构造控制要素,厘定了主要的围岩蚀变类型及空间展布规律,查明了引起各期蚀变事件的地质记录及矿化的空间分布规律,并探讨了成矿物质沉淀的机制,初步建立了该矿床的成矿模型。研究表明,驱龙铜矿中新世斑岩是闪长质深部岩浆房不断演化的产物,花岗闪长岩中新发现的、结晶时间为22.2Ma左右的闪长质包体可近似代表深部岩浆房组分,依次产出的花岗闪长岩、呈岩株或岩枝产出的P斑岩、X斑岩及最晚期的闪长玢岩(15.7±0.2)Ma,均为深部岩浆房连续演化的产物,岩浆持续6Ma左右。岩浆演化过程中角闪石、斜长石不断的结晶分异,导致了岩石常量元素、稀土元素及微量元素组成的规律性变化,斑岩埃达克质的特征也因岩浆演化过程中角闪石等矿物的不断结晶分异而引起。X斑岩中锆石的Hf同位素特征表明,岩石可能形成于新生下地壳的部分熔融。大面积产出的花岗闪长岩为驱龙铜矿最主要的含矿围岩,容纳了驱龙矿床70%以上的矿体,主要由斜长石、钾长石和石英组成,具花岗结构-似斑状结构,近EW向产出,其浅成就位可能受背斜控制,其后的各期斑岩均沿该侵位中心上侵,而冈底斯地壳中新世的快速抬升与剥蚀是导致含矿斑岩浅成侵位的根本原因;矿区内的SN向裂隙带既不控岩,也不控矿。浅成侵位的斑岩及深部岩浆房均发生了流体出溶。发生了大量流体出溶的深部岩浆房,是矿区早期蚀变流体的主要来源,显微晶洞构造及单向固结结构(UST)是流体出溶的地质记录。蚀变主要有3种类型,分别为早期的钾硅酸盐化、青磐岩化以及晚期的长石分解。钾硅酸盐化可分为2个阶段,即蚀变矿物以次生钾长石为主的早期钾硅酸盐化和以次生黑云母为主的晚期钾硅酸盐化。青磐岩化因产出的岩石类型不同,蚀变矿物组合具有明显差异性:产于叶巴组地层中的青磐岩化相对较强,蚀变矿物以绿帘石为主;产于花岗闪长岩中的青磐岩化相对较弱,蚀变矿物以绿泥石为主。晚期长石分解蚀变以破坏长石类矿物为特征,蚀变矿物主要为绢云母-绿泥石-粘土等。石英和硬石膏贯穿于上述各种蚀变中。空间上,钾硅酸盐化位于斑岩体及其周围地区,青磐岩化位于钾硅酸岩化外侧。后期形成的长石分解蚀变强烈叠加了早期钾硅酸盐化,介于钾硅酸盐化带与青磐岩化带之间。与早期钾长石化有关的脉体主要为不规则石英-钾长石脉,与晚期黑云母化有关的脉体主要为不规则至板状的石英-硬石膏脉、黑云母脉,与青磐岩化有关的脉体主要为板状的绿帘石-石英脉,与晚期长石分解蚀变有关的脉体主要为板状黄铜矿-黄铁矿脉及黄铁矿脉;在早期钾硅酸盐蚀变与晚期长石分解蚀变转换阶段,发育一组板状的石英-硫化物脉。早期不规则的脉体形成于斑岩结晶早期、矿区裂隙小规模发育阶段;晚期的板状脉体形成于斑岩弱固结或固结之后、矿区大规模连通裂隙发育阶段。驱龙矿区的铜矿化分布较为均一,主体产于花岗闪长岩中,其中,铜矿化主体形成于黑云母化蚀变阶段,转变阶段及长石分解阶段也有大量铜的形成;钼主要形成于转换阶段,长石分解蚀变阶段也有产出。黑云母化阶段,铜的沉淀与角闪石黑云母化、斜长石钾长石化过程中Ca2 的大量释放有关;转换阶段,铜钼矿化可能与压力和(或)温度骤降有关;晚期铜矿化与长石矿化蚀变阶段,斜长石绿泥石化、黑云母绿帘石化过程中Ca2 及Fe2 的释放有关。     

内蒙古敖包吐萤石矿床的Sr、Nd、Pb同位素地球化学特征

敖包吐萤石矿床是内蒙古北部苏莫查干地区单一萤石矿集区中的一个代表性矿床,产于早二叠世大石寨组火山-沉积岩与早白垩世敖包吐花岗岩的接触带上。文章通过分析该矿床岩、矿石的微量元素和稀土元素,揭示出萤石的成矿作用可分为2个阶段,即交代作用和充填作用。交代作用过程中大石寨组的结晶灰岩可能为萤石的形成提供了部分Ca来源,萤石矿石的稀土元素配分模式与海水基本类似,具有Ce负异常;成矿作用后期主要表现为充填作用,形成颗粒粗大的萤石,表现为重稀土元素富集的特征,并随着萤石的沉淀析出,稀土元素总量逐渐下降,反映出成矿流体经历了较长期的演化过程。各地层单元、花岗岩体和萤石矿石的Sr、Nd、Pb同位素研究表明,萤石的放射性同位素组成具有壳、幔源混合的特点,成矿物质来源具有多源性。早白垩世敖包吐花岗岩可能是萤石中F的主要来源,而大石寨组的结晶灰岩则可能提供了Ca。另外,Pb、Nd同位素的极大不均一性,有可能是成矿流体在运移过程中对艾力格庙群放射性组分的选择性吸收的结果。萤石成矿作用与钾玄岩的时空关系暗示了萤石的成矿过程可能是中国东部岩石圈减薄和下地壳的置换地质事件的结果。在构造转型的过程中,燕山中期富碱的酸性花岗岩浆的活动分异出富含F的成矿流体,与幔源流体混合,沿区域重新活化的深大断裂和大石寨组的层间破碎带上升,交代其间的灰岩透镜体,从而形成敖包吐中型萤石矿床。